The central processing unit (CPU) is the center of a computer. It processes data transferring from various kinds of devices, and transfers data to correct devices for executing after some judgments and calculations. Therefore, the CPU can be said to be the brain of a computer.
To prevent the electromagnetic interference (EMI) from affecting the operation of a CPU, there is already a kind of structure commercially available for preventing the EMI of a CPU. As shown in FIG. 1, a CPU 10a is mounted in a base 11a. The base 11a is then mounted in a motherboard 12a so that the CPU 10a can be fixed on the motherboard 12a. A shielding element 13a made of metal material is installed above the CPU 10a. The shielding element 13a is a rectangular plate with an opening 14a at the center thereof. Each corner of the shielding element 13a extends downwards to form a pin 15a having a reverse hook, as shown in FIG. 1A. The shielding element 13a covers over the CPU 10a with the four pins 15a mounted in corresponding connection holes 16a preset on the motherboard 12a so that the shielding element 13a can also be steadily positioned on the motherboard 12a, thereby providing electromagnetic shielding effect for the CPU 10a.
The top of the CPU 10a contacts with the bottom of a heat radiator 17a through the opening 14a of the shielding element 13a. A retaining element 18a is installed above the heat radiator 17a. The two ends of the retaining element 18a are fastened at the two sides of the base 11a so that the heat radiator 17a can be fixed on the CPU 10a. The heat generated by the CPU 10a can thus be conducted to the heat radiator 17a for increasing heat-radiating effect.
However, the shielding element 17a in prior art uses the pins 15a having reverse hooks to be hooked on the motherboard 12a. There is no electrically grounding function. Therefore, better shielding effect of EMI can not be achieved.
Moreover, when the shielding element 13a in prior art is to be assembled on the CPU 10a, it is necessary to align the four pins 15a of the shielding element 13a with the four connection holes 16a on the mother board 12a so as to successfully insert the four pins 15a in the four connection holes 16a. The operation is laborsome and time-consuming, resulting in inconvenience of the assembly of the shielding element 13a. More manpower will be wasted so that production cost can not be effectively reduced. Moreover, because the four pins 15a of the shielding element 13a have reverse hooks, it is difficult to dismount the shielding element 13a when the pins 15a are hooked in the connection holes 16a, resulting in inconvenience of the disassembly of the shielding element 13a.